/*
 moxl - Modular XML Library
 Copyright (c) 2007, Malcolm Sparks

 This program is free software; you can redistribute it and/or
 modify it under the terms of the GNU General Public License
 as published by the Free Software Foundation; either version 2
 of the License, or (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package moxl.xpath.axes;

import java.util.ArrayList;
import java.util.List;

import moxl.dom.MoxlAttribute;
import moxl.dom.MoxlElement;
import moxl.dom.MoxlNode;
import moxl.xpath.parser.types.NodeTestMatcher;

public class AttributeAxisStrategy implements XPathAxisStrategy
{
	private final XPathAxis axis;

	public AttributeAxisStrategy(XPathAxis axis)
	{
		this.axis = axis;
	}

	public Iterable<MoxlNode> getNodes(MoxlNode contextNode, NodeTestMatcher nodeTestMatcher) throws InvalidAxisForNodeException
	{
		if (contextNode instanceof MoxlElement)
		{
			return getAttributesMatchingNodeTest((MoxlElement) contextNode, nodeTestMatcher);
		}
		else
		{
			throw new InvalidAxisForNodeException(axis, contextNode);
		}
	}

	private Iterable<MoxlNode> getAttributesMatchingNodeTest(MoxlElement contextElement, NodeTestMatcher nodeTestMatcher)
	{
		List<MoxlNode> attributes = new ArrayList<MoxlNode>();
		for (MoxlAttribute attribute : contextElement.getAttributeMap())
		{
			if (nodeTestMatcher.matches(attribute))
			{
				attributes.add(attribute);
			}
		}
		return attributes;
	}

}
